Microstructure of annealed 12Cr13 stainless steel and its effect on the impact toughness

Abstract

The microstructure and its effect on impact toughness of the annealed 12Cr13 stainless steel were investigated by OM and SEM. The results show that the morphology of carbides is the main factor that influences the impact properties. Globular-like, block or strip-like carbides precipitated continuously during annealing. Fine globular-like carbides in the pre-existed martensite grains improved the impact toughness. Block or strip-like carbides at the grain boundaries or in the δ-ferrite grains are detrimental to the impact property. The annealing temperature has significant effect on the carbide precipitation behavior. With the annealing temperature increasing from 760°C to 860°C, carbides coarsen resulting in the decrease of the impact energy from 151 J to 106 J. The sample with only block or strip-like carbides has low impact energy of 5 J. © Copyright.